How to Grow Sweet Potatoes

Sweet potatoes thrive in warm climates and well-prepared soil, producing nutrient-rich tubers with minimal maintenance. Choosing the right variety, providing proper spacing, and ensuring consistent care lead to a successful harvest.

Strong root development, balanced fertilization, and effective pest management help maximize yield while maintaining plant health. Proper harvesting and storage methods extend shelf life, preserving their natural sweetness for months.

Published: February 20, 2025.

Intro to Sweet Potatoes

Sweet potatoes are a versatile, nutrient-dense crop known for their rich flavor and adaptability to various growing conditions.

Unlike regular potatoes, they belong to the morning glory family and develop underground tubers from sprawling vines.

Thriving in warm temperatures and loose, well-draining soil, they require a long growing season to reach maturity.

With proper care, they produce high yields and store well for extended use, making them a valuable addition to any home garden.

Choosing the Right Sweet Potato Variety

Selecting a suitable sweet potato variety increases the chances of a successful harvest. Different types offer unique flavors, textures, and growing conditions, making it important to match the variety to the climate and soil type.

Sweet potatoes come in various colors, including orange, white, and purple. Orange-fleshed varieties, such as Beauregard and Covington, grow well in many regions and develop a rich, sweet flavor when cured properly. White-fleshed types, like O'Henry, offer a milder taste and firmer texture. Purple-fleshed varieties, such as Stokes Purple, contain high levels of antioxidants and require a longer growing season.

Days to maturity vary between varieties. Fast-growing types, such as Georgia Jet, mature in around 90 days, while others may need 120 to 150 days. Short-season regions benefit from early-maturing varieties, ensuring tubers develop fully before the first frost.

Disease resistance is another factor to consider. Some varieties withstand common issues such as fusarium wilt and root-knot nematodes better than others. Choosing resistant types reduces the need for chemical treatments and helps maintain a healthy crop.

Local availability also influences variety selection. Checking with nearby nurseries or agricultural extensions provides insight into the best-performing types for specific regions. Sweet potatoes adapted to local conditions tend to produce higher yields and require less maintenance.

Preparing the Soil for Optimal Growth

Well-prepared soil creates the best conditions for sweet potato plants to develop strong roots and produce high-quality tubers. Loose, sandy loam with good drainage allows roots to expand easily and prevents excess moisture from causing rot. Compact or clay-heavy soil restricts growth and may lead to misshapen or undersized sweet potatoes.

Soil preparation starts with clearing the planting area of weeds and debris. Removing large rocks and breaking up compacted soil improves aeration. Raised beds or mounds enhance drainage and create a warmer environment for the roots, which is especially beneficial in cooler climates.

Sweet potatoes thrive in slightly acidic to neutral soil, with an ideal pH range of 5.8 to 6.5. Testing the soil (Amazon link, opens in the new window) before planting helps determine whether adjustments are needed. If the pH is too low, adding lime raises it gradually. High pH levels can be corrected with sulfur or organic amendments such as pine needles or peat moss.

Organic matter, such as compost or well-aged manure, improves soil structure and provides essential nutrients. Mixing in compost before planting enriches the soil with nitrogen, phosphorus, and potassium. However, excessive nitrogen can lead to excessive vine growth at the expense of tuber development. Balanced fertilization ensures healthy foliage while promoting underground growth.

Avoiding freshly tilled ground helps prevent issues such as soil compaction and nutrient imbalance. Preparing the soil a few weeks before planting allows organic matter to break down and integrate fully. Mulching the surface with straw or grass clippings conserves moisture and suppresses weeds, creating a more favorable environment for young plants.

Sweet Potatoes Companion and Antagonist Plants

Here is the short list of good sweet potato plants' neighbors:

• Beans – As nitrogen-fixing plants, beans enrich the soil by increasing nitrogen levels, which helps sweet potatoes grow strong and healthy. Their upright growth minimizes competition for space.
• Peas – Like beans, peas also improve soil nitrogen and support sweet potato growth. Their shallow root system reduces competition for underground space.
• Thyme – This aromatic herb repels common pests like weevils and beetles that can damage sweet potato crops. Its low-growing habit works well alongside sprawling vines.
• Dill – Attracting beneficial insects such as ladybugs and predatory wasps, dill helps control aphids and other pests. It thrives in similar growing conditions without interfering with sweet potato development.
• Marigolds – Known for their ability to deter nematodes and insect pests, marigolds improve soil health and protect sweet potato roots. Their bright flowers also attract pollinators.
• Radishes – Acting as a natural trap crop, radishes lure pests away from sweet potato vines. Their quick growth makes them a useful addition to the garden.
• Spinach – As a low-growing leafy green, spinach provides ground cover that helps retain soil moisture and suppress weeds without competing for nutrients.

• Oregano – This fragrant herb repels common garden pests while requiring minimal space, making it a great companion for sweet potatoes. Its flowers attract pollinators, supporting overall plant health.
• Yarrow – Attracting pollinators and predatory insects, yarrow enhances biodiversity in the garden. Its deep roots do not interfere with sweet potato tubers.
• Alyssum – Acting as a living mulch, alyssum suppresses weeds and retains moisture while attracting beneficial insects. Its shallow roots allow sweet potatoes to grow undisturbed.

However, some plants should NOT be planted near sweet potatoes, including:

• Tomatoes – Both tomatoes and sweet potatoes are susceptible to similar pests and diseases, including root rot and blight. Planting them together increases the risk of soil-borne infections spreading between crops.
• Squash – As another vining plant, squash competes with sweet potatoes for space, sunlight, and nutrients. Their sprawling growth can lead to overcrowding, reducing airflow and increasing the risk of fungal diseases.
• Sunflowers – These tall plants produce compounds that inhibit the growth of nearby crops, including sweet potatoes. Their deep root system also competes for soil nutrients and moisture.

• Brassicas (Cabbage, Broccoli, Cauliflower) – Brassicas have heavy nutrient demands that deplete the soil, reducing the resources available for sweet potatoes. They also attract pests like cabbage worms, which may spread to nearby crops.
• Carrots – Both carrots and sweet potatoes require loose, well-draining soil, but they compete for underground space. Their root systems can interfere with each other’s growth, leading to misshapen or stunted tubers.

Starting Sweet Potato Slips: What You Need to Know

Sweet potatoes are grown from slips, which are small sprouts that develop from mature tubers. Unlike regular potatoes that grow from cut pieces, sweet potatoes require these shoots to establish healthy plants. Growing slips at home ensures strong, disease-free plants suited to local conditions.

Slips can be started indoors about six to eight weeks before the last expected frost. A warm, humid environment encourages sprouting. To begin, select a firm, healthy sweet potato from an organic source to avoid chemical treatments that prevent sprouting. Cutting the tuber in half and placing it in a jar with the cut side submerged in water helps speed up the process. Another method involves burying the tuber in moist sand or potting mix, with about half of it exposed.

Slips emerge within two to four weeks when kept in temperatures between 75°F and 85°F (24°C to 29°C). Once sprouts reach four to six inches in length, they can be gently twisted off the tuber and placed in water to develop roots. After a few days, well-rooted slips are ready for planting. If immediate planting is not possible, storing slips in damp paper towels or keeping them in water for a few days maintains their viability.

Ensuring slips remain healthy before transplanting increases survival rates. Strong roots and vibrant green leaves indicate they are ready for outdoor conditions. Gradually exposing slips to sunlight for a few hours daily helps them adjust before full planting.

When and Where to Plant Sweet Potatoes

Sweet potatoes require warm soil and frost-free conditions to grow properly. Planting too early in cold soil stunts development, while delaying too long reduces the growing period needed for mature tubers. The best time for planting is two to four weeks after the last frost, when soil temperatures consistently reach at least 60°F (16°C).

A sunny location with at least six to eight hours of direct sunlight per day provides the best conditions for vine growth and tuber production. Choosing a well-draining site with loose, fertile soil allows roots to expand freely. Raised beds or rows improve drainage and help warm the soil faster in cooler regions.

Spacing plays a significant role in plant health and yield. Placing slips 12 to 18 inches apart in rows spaced 36 inches apart gives vines enough room to spread while preventing overcrowding. Deep planting should be avoided, as slips establish better when the roots are buried, but leaves remain above the soil.

Watering immediately after planting helps slips take root. Moisture is important in the early weeks, but excess water should be avoided to prevent rot. A light layer of mulch conserves moisture, regulates temperature, and suppresses weeds, giving young plants a strong start.

Proper Spacing and Planting Techniques

Providing enough space between sweet potato plants allows vines to spread while ensuring tubers have room to develop underground. Proper spacing prevents overcrowding, improves air circulation, and reduces the risk of disease.

Slips should be planted 12 to 18 inches apart in rows spaced three to four feet apart. This distance allows vines to extend naturally while minimizing competition for nutrients and sunlight. Planting too close together restricts airflow, increasing the likelihood of fungal diseases such as powdery mildew. Wider spacing leads to larger, well-formed tubers, while overly dense planting may result in small, irregularly shaped roots.

Slips should be inserted two to three inches deep, with only the lower portion of the stem buried and leaves remaining above the soil. Covering the base firmly encourages strong root establishment while preventing excess moisture buildup around the stems. If planting in raised beds or containers, maintaining at least 10 to 12 inches of soil depth allows roots to expand without restriction.

Sweet potatoes thrive in warm soil, and raised rows or ridges help increase soil temperature and improve drainage. Forming ridges about eight to ten inches high and planting slips along the top enhances root aeration and reduces the risk of waterlogging. This technique is especially useful in regions with heavy rainfall or clay-rich soil.

Mulching around plants helps retain moisture, suppress weeds, and regulate soil temperature. A layer of straw, grass clippings, or compost applied around the base of the plants prevents soil from drying out too quickly while keeping developing tubers protected from direct sunlight.

Watering Sweet Potatoes: Best Practices

Consistent moisture is essential for healthy growth, but excessive watering increases the risk of rot and poor tuber formation. Establishing a proper irrigation schedule improves plant resilience and ensures an abundant harvest.

Newly planted slips require deep watering immediately after transplanting to help roots establish in the soil. During the first two weeks, soil should remain evenly moist but not soggy. Frequent light watering encourages root expansion, supporting early vine development.

Once plants are established, watering should be adjusted based on weather conditions. Sweet potatoes thrive in moderate moisture levels, with an ideal range of one to one and a half inches of water per week from rainfall or irrigation. If soil dries out too quickly, deep watering once or twice a week keeps roots hydrated.

Excessive watering leads to problems such as root rot and cracking tubers. Soil that remains wet for long periods prevents oxygen from reaching the roots, causing tubers to deteriorate. To prevent this, watering should be done in the morning to allow excess moisture to evaporate throughout the day.

As harvest approaches, reducing water intake improves tuber quality. Around two to three weeks before harvesting, limiting irrigation encourages the skins to toughen, increasing their ability to store well after harvest. This final adjustment ensures sweet potatoes develop a rich flavor and long shelf life.

Fertilizing for Strong Growth and High Yields

Sweet potatoes thrive in nutrient-rich soil, but excessive fertilization can lead to vigorous vine growth at the expense of tuber development. A balanced approach ensures plants receive the necessary nutrients without encouraging excessive foliage.

Before planting, incorporating well-aged compost or organic matter into the soil improves fertility and structure. A soil test helps determine existing nutrient levels and reveals whether additional amendments are needed. A pH level between 5.8 and 6.5 supports optimal nutrient absorption.

A low-nitrogen fertilizer, such as 5-10-10 or 8-24-24 (Amazon links, open in the new windows), is recommended to promote root growth rather than excessive leaf production. Fertilizer should be applied at planting and again four to six weeks later. Too much nitrogen causes lush vines but small or underdeveloped tubers, while insufficient potassium reduces overall yield.

Side-dressing with compost or a balanced organic fertilizer midway through the growing season helps maintain steady nutrient availability. Wood ash or bone meal provides additional potassium and phosphorus, supporting healthy tuber formation. Granular fertilizers should be applied four to six inches away from the plant base to avoid direct contact with the roots, preventing potential damage.

Liquid fertilizers or compost tea can be used periodically but should be applied sparingly. Excessive feeding later in the season may delay tuber maturity. Keeping fertilization balanced ensures plants focus energy on producing well-formed, nutrient-rich sweet potatoes.

Managing Weeds and Mulching for Healthier Plants

Weeds compete with sweet potatoes for nutrients, sunlight, and moisture, reducing yields if left unmanaged. Controlling weed growth early in the season prevents them from becoming difficult to remove once vines spread.

Regular shallow cultivation keeps weeds under control without disturbing delicate sweet potato roots. Pulling weeds by hand or using a hoe in the early weeks prevents competition and allows young plants to establish. Deep cultivation should be avoided, as sweet potatoes develop close to the soil surface and may become damaged.

Applying organic mulch around plants suppresses weed growth while helping retain soil moisture. A two to three-inch layer of straw, grass clippings, or dried leaves blocks sunlight from reaching weed seeds, reducing germination. Mulch also prevents soil compaction, keeping the ground soft and aerated for better root expansion.

Black plastic mulch is another effective method, particularly in cooler climates where it helps warm the soil. Covering the planting area with plastic before transplanting encourages faster vine growth while keeping weeds from sprouting. However, organic mulch remains a better option for moisture retention in dry regions.

Weed management is most important in the first six to eight weeks, before vines spread and create natural ground cover. Once sweet potatoes develop a dense canopy, weeds struggle to compete, reducing the need for additional maintenance. Proper mulching and early weed control contribute to healthier plants and higher yields.

Protecting Sweet Potatoes from Pests and Diseases

Sweet potatoes are generally hardy, but pests and diseases can reduce yield and quality if left unchecked. A proactive approach helps prevent infestations and infections, ensuring a healthy crop.

Common Pests

• Sweet Potato Weevils lay eggs in vines and roots, causing damage both above and below the soil. Infested tubers develop dark patches and become bitter. Planting weevil-resistant varieties and rotating crops every year reduces their impact. Removing plant debris at the end of the season eliminates overwintering sites.
• Wireworms burrow into developing tubers, creating small holes that lower market quality. Keeping the soil free of weeds before planting and avoiding recently turned sod minimizes their presence. Using bait traps, such as buried chunks of potato, helps monitor and control wireworm populations.
• Flea Beetles chew small holes in leaves, weakening young plants. Floating row covers offer protection until vines establish. Applying diatomaceous earth or neem oil reduces damage without harming beneficial insects.

Common Diseases

• Black Rot appears as dark, sunken lesions on tubers and is caused by a fungal infection in contaminated soil. Rotating crops and selecting disease-free slips prevent its spread. 
• Curing harvested tubers in a warm, dry environment helps resist infection.
• Fusarium Wilt causes yellowing and wilting leaves, often due to soilborne fungi. Ensuring proper drainage and planting resistant varieties lowers the risk.
• Scurf leads to dark patches on tuber skins, making them unattractive but still edible. Avoiding excessive moisture and practicing good crop rotation reduces its occurrence.

Maintaining proper spacing and keeping vines dry helps minimize fungal growth. Healthy soil with good drainage and organic matter supports plant immunity. Companion planting with marigolds deters pests naturally, reducing reliance on chemical treatments.

How to Know When Sweet Potatoes Are Ready to Harvest

Sweet potatoes require a long growing season, typically maturing in 90 to 150 days, depending on the variety. Harvesting too early results in underdeveloped tubers, while leaving them in the ground too long increases the risk of skin damage or decay.

The first sign of maturity is yellowing and dying back of the vines. When foliage begins to wilt and turn brown, tubers have likely reached full size. Checking the calendar and comparing with the expected maturity date for the planted variety also helps determine readiness.

Gently digging up a few tubers from the edge of the planting area provides a clear indication of size and development. If tubers have reached their expected length and girth, the entire crop is likely ready for harvest. Thick, well-formed roots with firm skins indicate they are mature.

Harvesting should take place before the first frost, as cold temperatures damage tubers and reduce storage life. Using a digging fork or spade, carefully loosening the soil around plants prevents cuts and bruises. Sweet potatoes should be handled gently, as fresh skins are delicate and can tear easily.

Once harvested, tubers should be left in a warm, dry area for a few hours to allow excess moisture to evaporate. Proper curing enhances their sweetness and extends storage life, ensuring a high-quality yield.

Harvesting Sweet Potatoes Without Damaging the Roots

Sweet potatoes are delicate at harvest, and rough handling can lead to bruising or skin damage, reducing their storage potential. A careful approach ensures tubers remain intact and ready for long-term use.

Harvesting should be done on a dry, warm day, preferably when the soil is not overly wet or compacted. Soft soil makes it easier to lift tubers without excessive pulling or twisting, which can cause breakage. Using a digging fork or spade, loosening the soil around plants about 12 to 18 inches from the base prevents accidental cuts. A slow, gentle lift exposes the tubers without breaking them.

After uncovering the sweet potatoes, shaking off excess soil instead of washing them helps maintain their natural protective coating. Freshly dug tubers have fragile skins that can tear easily, making them more vulnerable to rot. Allowing them to dry in the shade for a few hours helps toughen the skin slightly before further handling.

Sorting the harvest based on size and quality prevents damaged tubers from affecting healthy ones during storage. Any sweet potatoes with cuts or bruises should be used first, as they will not store as long as those with intact skins. Proper handling at this stage ensures a high-quality yield that will last for months when stored correctly.

Curing and Storing Sweet Potatoes for Long-Term Use

Freshly harvested sweet potatoes contain excess moisture and starch, making them less sweet and more prone to spoilage. Curing allows the tubers to develop their characteristic flavor while sealing minor wounds, extending their shelf life.

Curing requires a warm, humid environment to convert starches into sugars and harden the skins. Ideal conditions include temperatures around 80–85°F (27–29°C) with humidity levels of 85–90% for about 10 to 14 days. Placing tubers in a well-ventilated room, greenhouse, or covered area with slight airflow helps maintain these conditions. A small fan can improve air circulation if needed.

Once cured, sweet potatoes should be stored in a cool, dark, and well-ventilated space. Ideal storage temperatures range between 55–60°F (13–16°C), with moderate humidity to prevent shriveling. Storing them in crates, baskets, or ventilated boxes lined with paper prevents moisture buildup while keeping tubers dry.

Avoid refrigerating sweet potatoes, as temperatures below 50°F (10°C) cause internal damage, leading to an unpleasant texture. Keeping them away from direct sunlight or heat sources also prevents sprouting or drying out. Properly cured and stored tubers can last six months or more, retaining their sweetness and firm texture.